Texas Instruments TPS23785B High-Power High Efficiency PoE PD & DC-to-DC Controller is a combined Power over Ethernet (PoE) powered device (PD) interface and current-mode DC-to-DC controller optimized specifically for non-isolated converters. The PoE interface supports the IEEE 802.3at standard. The TPS23785B supports a number of input voltage ORing options including highest voltage, external adapter preference, and PoE preference. These features allow the designer to determine which power source will carry the load under all conditions. The PoE interface features the two-event, physical-layer classification necessary for compatibility with high-power midspan power sourcing equipment (PSE) per IEEE 802.3at. The detection signature pin can also be used to force power from the PoE source off. Classification can be programmed to any of the defined types with a single resistor.